The present invention relates to tandem drives and more specifically relates to driver and driven shaft mountings for such drives.
Some vehicles, of which motor graders are an example, have tandem drive wheels which are driven by means of a tandem drive including a tandem housing having a driver shaft mounted centrally therein and carrying a double sprocket which is drivingly connected by respective chains to sprockets carried by a pair of driven shafts which are mounted on opposite sides of the driver shaft. Lubrication for the tandem drive is provided by oil located within the tandem box.
Conventionally, proper spacing between the driver and driven shafts is maintained by providing precisely spaced, machined pilot openings in the tandem housing, with extensions of respective housings supporting the driver and driven shafts being received in the pilot openings. Also, it is conventional to seal these pilot openings for preventing the loss of lubricant by providing each of the shaft housing extensions with an O-ring groove which receives an O-ring that seals against a respective one of the machined openings.
The machining of the relatively large pilot holes is quite time consuming, and of course a certain amount of material is necessary to form extensions on the shaft housings. Also, the seal surface between the extensions and the tandem housing wall is quite narrow, and therefore sealing is not as problem-free as it might be if the surface were wider.